A Minnesota waitress who says a customer told her she could keep a box containing $12,000 has sued after police impounded the cash as suspected drug money.

Stacy Knutson of Moorhead, Minn., filed a lawsuit asking that the cash be returned to her. She said she believes the money was meant as an anonymous gift from someone who knew that she, her husband and five children were struggling with severe financial difficulties.

"I do know that the person gave me what was in that to-go bag," Knutson wrote in the lawsuit filed in March. "Thus as I understand it, it is mine."

A message left at Knutson's home Wednesday was returned by her attorney, Craig Richie, who said his client is "overwhelmed" and didn't want to speak to a reporter.

The lawsuit says Knutson was working at the Fry'n Pan restaurant when a customer left behind a takeout box from another restaurant. She followed the diner to her car and tried to return the box but the lady said, "No, I am good, you keep it," the lawsuit said.

When Knutson went back into the kitchen and opened the box, she found three wads of bills — $100s, $50s, $20s and $10s — wrapped in rubber bands, Richie said.

Even though she really needed the money, she decided to call police, her attorney said.

Officers told her to wait 90 days in case someone claimed the money. No one did but police still refused to return the cash, saying it was being held in a drug investigation because it smelled of marijuana, Richie said.

But if Knutson believed the diner was the rightful owner of the cash, and that the diner gave her explicit permission to keep the money, why would Knutson even bother going to police?

"She's saying, hey, this is a lot of money," Richie said. "She doesn't want to be in a position where she's doing something wrong."

After no one claimed the money, that confirmed for her that the money was truly a gift, Richie said.

Moorhead police Lt. Tory Jacobson said when money is usually found and turned over to police, the finder can keep it if no one claims it in 90 days. But in a narcotics case, the money goes to the county attorney's office unless the finder persuades a judge to award the cash to them, he said.

"That doesn't mean she can't raise the issue with the judge," Jacobson said of Knutson. "It's just not the police department's decision to make."

Richie said police told him they smelled marijuana on the bills and that a police dog confirmed their suspicions. Jacobson acknowledged that a police dog detected an unspecified drug.

But Richie said at least one of Knutson's co-workers took a deep whiff of the bills to jokingly see what that much money smells like, and the man didn't detect any scent of marijuana.

And even if the bills did smell of drugs, Richie said that doesn't give police the right to keep them. Jacobson declined to comment, citing the ongoing investigation.

The lawsuit says Knutson is not being accused of having anything to do with drugs herself.

Knutson said she was convinced about what really happened: that the windfall was God's way of answering her family's prayers.

"It is a complete miracle to see our prayers answered," she wrote, "but then difficult to face the reality of the struggle it is to obtain it (the money) from the Moorhead Police Department."